1. Field
Embodiments of the invention relate to electronic devices, and more particularly, to bias circuits for amplifiers.
2. Description of the Related Technology
An amplifier, such as an operational amplifier or an instrumentation amplifier, can include one or more transconductance amplification blocks to aid in achieving a desired performance characteristic. For example, the amplifier can include a pair of transconductance amplification blocks arranged in an indirect current-feedback configuration to improve the operational input voltage range of the amplifier.
Including one or more transconductance amplification blocks in an amplifier can impact the amplifier's performance. For example, variation in drain current and/or drain-source voltage of field-effect transistors disposed at the inputs of the transconductance amplification block can impact the nonlinearity and/or common-mode rejection ratio (CMRR) of the amplifier.
There is a need for transconductance amplification blocks having improved performance. Additionally, there is need for amplifiers having improved linearity, CMRR, and that can operate over a wide range of input voltages.